Sealed toggle switch with led switch

ABSTRACT

A water- and/or dust-tight toggle switch has an LED switch. The LED or other luminous elements are impermeably shielded from the surroundings by a housing of a comparatively simple design. The housing is provided with cast windows which make possible light output from the luminous element disposed within the interior of the housing. Favorable refinements pertain to the arrangement of a light guide on the actuator cap and also the protection of the inserted plug through extended, guided-down housing walls.

BACKGROUND OF THE INVENTION

For a number of practical applications it is necessary to have toggleswitches which are designated to be water- and/or dust-tight. In DE-GM18 04 987 a watertight toggle assembly on the housing cover of a switchis suggested. Another proposal for a seal of this type is indicated inDE-GM 71 09 985. Yet another requirement concerning these switches isthat they should have an LED display which is intended to assist inlocating the switch in the dark (seek function) and/or which is intendedto display the switch status of the toggle switch and/or the function(functional display) switched with the toggle switch.

DE-OS 30 24 510 proposes that a filament lamp be placed in a separatechamber of the housing, which is separated from the chamber used by theswitch contact. In this case, the light is only conditionally shieldedagainst surrounding factors, whereas on the other hand, a comparativelycomplicated shape of the housing results.

It is desired to further improve a switch of this type so that the shapeof the housing will be simplified and the luminous element is betterprotected against surrounding influences.

SUMMARY OF THE INVENTION

A lamp is included in the enclosed chamber and the housing itself isprovided with a suitable window, through which the light flux can moveinto the interior space of the actuation key, where it then lights upsymbols or windows located in the usual manner at the bottom of the keyand is used to impart information to the operator.

In order to be able to emit most of the output light flux from theluminous element through the housing into the key space, the housing hasa dome-like bulge with the window in it protruding end surrounding thelamp. Of course, this property can also be applied when using severallights in the switch and even with several lights for one key. Moreover,the stated structure is very space-saving and due to the steep, lateraldome walls, creates additional possibilities for sealing, as will beexplained further below.

In yet another refinement of the invention, in order to prevent a morecomplicated cast shape, and, for example, when using several luminouselements, to be able to use the function display and/or seek display bymere disassembly or rotated installation of the key cap, it isrecommended to have, for the actuation key, a pivot mounted actuator onwhich a cap engages.

In order to obtain a strong brightness contrast in the functionallighting depending on the selected function, a light guide attachedopposite the window and in the front wall in one toggle position of thekey is also recommended. Thus, a light guide connected to the cap and tothe key can be guided close to the vicinity of the associated lightwindow in the housing, and therefore in the vicinity of the luminouselement; secondly, it can be removed from the light guide by the pivotmotion of the key. Thus, the light guide can be positioned so that dueto the pivoting motion, the angle of incidence of the light, in the onecase, can be simultaneously brought into a position favorable fortransmission, and in the other case, it can be brought into a positionunfavorable for transmission.

A particularly favorable configuration for the light guide for theabove-mentioned requirements can be found using a cup-like end piece. Inorder to obtain a particularly strongly-lit light display area on thesurface of the key and/or the cap facing the observer, it isrecommended, in a refinement of the invention, to fix the light guide tothe cap. Accordingly, the light guide is conducted directly through thebase of the cap, so that its end is visible to the observer. Thus theobserver can directly perceive the light flux emitted from the end ofthe light guide. In this case, the light guide can also have the sidecontour of a symbol, so that this symbol then lights up very strongly inthe appropriate switch setting.

As already mentioned, in order to be able to make significant changes inthe light flux transmitted through the light guide as a function of theposition of the toggle switch, in a refinement of the invention, it isrecommended to position the light guide at an angle to the axis of theactuator lever. In order to obtain an additional protection in theterminal area of the switch, in a refinement of the invention, the baseelement is inserted relatively deeply into the interior of the housing,or stated differently, the side walls of the housing are pulled downover the side surface of the base plate in order to shield it laterallyagainst surrounding factors.

Additional protective measures can consist in preventing pollutants frommoving across the side surfaces of the plug-in contacts of a terminal tobe plugged into the plug connector of the switch. In this case, theplug-in contacts of the plug connector to be plugged in are carefullyinsulated from each other, which can take place by means ofcorresponding sealing material or by casting of the plug contacts intothe plug. Thus, as an added or optional feature, the outer contour ofthe plug connector against the guided-down side walls of the housing canbe sealed by means of an appropriate sealing strip, so that neither dirtnor moisture can get into the preferably blade-shaped plug-in contactsof the switch.

In order to prevent any dust or moisture from settling on the frontsurface of the housing and having an adverse effect on lightpermeability of the housing windows and/or the sealing of the key in thehousing, receptacle spaces are provided in the front surface of thehousing and the lateral covers can pivot into them during the togglemotion of the key. Side walls of these spaces can be defined, forexample, by the side walls of the housing bulges described above andwhich are used to hold the luminous elements. With the inserted covers,a labyrinth difficult for dust or water to overcome can be obtained. Atthe same time, the receptacle space can be used for collection of dirtor moisture to prevent it from entering the windows of the front surfaceof the housing located further up.

An additional measure to keep the front surface of the housing free ispresented by the key which covers the front surface of the housing likea shield.

As was explained above, the switch of the invention is suitable not onlyfor holding a single luminous element, but also for holding two or moreluminous elements. If two luminous elements are used, the symmetriclocation of the second luminous element to the first is recommended.Accordingly, it is also possible to solve different problems with thesimilarly-designed switch in that in various settings, the key engageswith the switch and/or the key cap with the actuator.

In order to ensure that the second luminous element always properlyfulfills a search function, the illumination of the interior space bymeans of a window or opening is recommended. Accordingly, threetransparent elements essentially aligned with each other independentlyof the switch setting are provided, wherein the first is designed as awindow in the housing front, the second as an opening or window in theactuator, and the third as a light-permeable symbol or, under certaincircumstances, a simple, colored window.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal section through the switch of the invention.

FIG. 2 is a side view of one possible connector plug for a switchaccording to FIG. 1.

FIG. 3 is a cross section through the switch according to FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The present description deals with a further development of the subjectmatter of published German patent application No. 30 24 510. The presenta document describes only properties which are new with respect to thisdescription and essential to the present invention. The switch accordingto FIG. 1 features a housing 1 whose case side walls 2 are pulled fardown and thus are used for protection of the connection strip of thebase element 3. It is particularly important for the invention that thehousing have on its upper end in FIG. 1, a solid front wall 4 whichnecessarily is interrupted only in one small, carefully sealed area inwhich an extension of the key 5 extends into the interior space 6 of thehousing 1.

The base element 3 is inserted from below into the housing and engageswith it. Contact blades 7 extend through and are cast with the baseelement; in a known manner these blades are connected to the fixed-siteand also to the moving contact pieces 43 of a rocker contact. Actuatorlever 42 is disposed between seal 20 and contact piece 43. In addition,the contact blades are connected in a suitable format to two luminouselements 8 and 9, wherein the luminous element 8 is used for functionlighting and the luminous element 9 is used for search lighting. In thiscase, the lamps are held in mounts connected with the housing. Thus inthe first place, the connection lines can be used to mount the luminouselements 8, 9. But the mounts can also be clamped between the side wallsof two recesses 10, 11 of the front wall 4 of the housing 1. The mode ofoperation of the switch elements of the switch corresponds to that ofthe switch described in DE-OS 30 24 510 and is thus not repeated at thispoint.

It is particularly important for the invention that the two luminouselements 8, 9 be located in the interior space of the housing 1 andcovered by the solid front wall 4. In order that the light flux emittedfrom the luminous elements 8, 9 can also reach and pass through the key5, the front wall 4 is provided with two windows 12, 13 which arespherically bulged, transparent and cast with the housing 1. In thefront wall, the key 5 is seated in a known manner (see DE-OS 30 24 510or DE-AS 12 12 616 or DE-GM 18 04 987). In this case, the key 5 iscomposed of an actuator 14 and a cap 15, wherein the cap 15 engages withthe actuator 14. Due to the division of the key 5 a simplified castshape is obtained. The two part composition also enables the possibilityof using the switch of the invention for other switching tasks merelythrough rotated installation of the cap 15 onto the actuator 14.

Particularly advantageous for the switch are the bag-like receivingspaces 16, 17 formed by the side walls 2 of the housing and the sidewalls of the bulges 10, 11 in the front wall, since possibly dust ormoisture may collect there on the outer surface of the front wall 4. Atthe same time, the ends of two covers 18, 19 set on the sides of theactuator 14 penetrate the receiving spaces 16, 17 during the pivoting ofthe key 5, and thus block the path for dust and water on the surface ofthe front wall 4. Thus, in addition, the windows 12, 13 and the seal 20of the key 5 are kept free from dirt with respect to the housing 1. Inthis case, the receiving spaces 16, 17 can be connected to each other bymeans of a running groove, into which a running wall linking the covers18, 19 together is inserted.

A light guide 21 can engage in or be cast with the cap 15. The end 22 ofthe light guide forms a window in the surface of the cap 15 which can belit very brightly. The contour of the end of the light guide 22 can alsobe configured as a symbol. The shaft 23 of the light guide passes into acup 24 which surrounds the bulged window 12 in the front wall 4 and thusreceives the light flux penetrating through this window and via theshaft 23 transfers it to the end 22 of the light guide. Whereas in theposition shown in FIG. 1, the light passage from the window 12 to thecup 24 and thus to the light guide 21 is very simple, in a second tiltedposition of the key 5 not shown in FIG. 1, the cup is raised above thewindow 12 and oriented at an oblique angle to it. Thus the light comingfrom the window 12 can hardly enter the cup 24, so that due to the darkend 22 of the light guide, the switch setting not illustrated in FIG. 1will be indicated to the operator.

But in order to provide an equivalent indication of the position of theswitch to the operator in the dark, a second luminous element 9 is used,whose light, via the window 13 and a recess 25 (which can also beconfigured as a window) in the actuator 14 and also a light-permeablewindow 26 in the cap 15, can reach the observer. The window 26 can havethe contour of a symbol and be cast into the cap 15 or it can belight-permeable due to a corresponding thinning of the window region 26.But in particular, it is recommended to make the inner surface of thecap 15 reflective by means of a white coating or a spray-coated whitelayer, which can serve simultaneously as window 26.

FIG. 2 shows the possibility of designing a plug connector suitable forsealing of the switch according to FIG. 1. In this case, the plugconnector can have laterally protruding brackets 30, 31 on the plughousing 29, which, in the first place, ensures a sealing between plug 28and the connection strip of the switch in conjunction with the sidewalls 2, and, in the second place, enables engagement of the plug 28 inthe switch housing 1. The receiving contacts 32 to 37 can be cast forimproved sealing, either in the housing 29 or its surroundings, by meansof a sealing material 33.

In the symmetrical arrangement of the luminous elements 8, 9, it isparticularly favorable that in the one key position with light guide 24seated on the front wall 4, the switched-on function at the end 22 ofthe light guide is indicated particularly clearly. But in the otherposition, due to the pivoting window 26 toward the luminous element 9 inthe switched-off state of the functional lighting, the search lightingis particularly easy to see. As explained above, FIG. 3 shows how thecovers 18, 19 are designed by means of lateral walls 38, 39 as a runningwall. The same also applies to the receiving spaces 16, 17, which, as isevident in FIG. 3, can be interconnected in the longitudinal directionof the switch so that a channel 40 is created into which the runningwall is inserted.

We claim:
 1. An illuminated sealed toggle switch comprising:a housinghaving a continuous front wall enclosing a luminous element with awindow of light-permeable material over the luminous element; anactuation key pivotally mounted to the front wall of the housing andacting on a moving contact piece disposed within the housing, theactuation key including a pivot mounted actuator on which a cap engages;and a light guide having two ends, the first of which being attached tothe cap and the second of which being located adjacent to the window inthe front wall and being a cup-like end piece enclosing a section of ahousing bulge with the window in a corresponding toggle position of thekey.
 2. A switch as claimed in claim 1 wherein the front wall has atleast one dome-like bulge which has on a protruding end thereof thewindow with the bulge surrounding the luminous element.
 3. A switch asclaimed in claim 1 wherein the first end of the first end of the lightguide extends through the cap and is exposed for viewing to a switchoperator.
 4. A switch as claimed in claim 1 wherein the light guide ispositioned at an angle to a longitudinal axis of the actuator leverbranching off from the cap.
 5. A switch as claimed in claim 1 wherein alower end of the housing has a base element bearing the switch contactsand also a connector plug and the housing has side walls extending pastfree ends of the connector plugs, forming control walls for theconnector plugs.
 6. A switch as claimed in claim 1 wherein one of thecap and the actuator of the key is provide with covers facing thehousing which during toggle motion of the key enter into receivingspaces associated with the covers in the housing.
 7. A switch as claimedin claim 1 wherein a second luminous element is located within thehousing essentially symmetrical to the first luminous element.
 8. Aswitch as claimed in claim 7 wherein the second luminous elementilluminates an interior space of the key by means of a window of thehousing.
 9. A switch as claimed in claim 8 wherein the actuator has anopening aligned with the second luminous element for illumination of aninterior space of the key.